VM: Store edge counters in one per-function array.

runtime/vm/intermediate_language_arm64.cc

Index: runtime/vm/intermediate_language_arm64.cc
diff --git a/runtime/vm/intermediate_language_arm64.cc b/runtime/vm/intermediate_language_arm64.cc
index 7ae62c03ef4991e398c4dca35528622f2d16feb9..9b7585d33ea1fea71bf8d2f75357597a18f5cb93 100644
--- a/runtime/vm/intermediate_language_arm64.cc
+++ b/runtime/vm/intermediate_language_arm64.cc
@@ -5415,13 +5415,10 @@ LocationSummary* GotoInstr::MakeLocationSummary(Zone* zone,
 void GotoInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   if (!compiler->is_optimizing()) {
     if (FLAG_emit_edge_counters) {
-      compiler->EmitEdgeCounter();
+      compiler->EmitEdgeCounter(block()->preorder_number());
     }
     // Add a deoptimization descriptor for deoptimizing instructions that
-    // may be inserted before this instruction.  On ARM64 this descriptor
-    // points after the edge counter code so that we can reuse the same
-    // pattern matching code as at call sites, which matches backwards from
-    // the end of the pattern.
+    // may be inserted before this instruction.
     compiler->AddCurrentDescriptor(RawPcDescriptors::kDeopt,
                                    GetDeoptId(),
                                    Scanner::kNoSourcePos);